Renal Control of Blood Pressure

Question 1

• What receptors are involved in detecting reduced blood pressure?

Answer 1

Baroreceptors

Question 2

• Mean arterial pressure (MAP) =

Answer 2

Cardiac output (CO) x total periphery resistance (TPR)

Question 3

• How do the kidneys control blood pressure?

Answer 3

Pressure diuresis – control pressure by regulating urinary output of Na+

Question 4

• How does RAAS act to control blood pressure?

Answer 4

Direct increase in salt and water retention, indirect effect via aldosterone

Question 5

• What is the most common cause of secondary hypertension?

Answer 5

Kidney-related disorder – increased Na retention, decreased Na excretion or decreased RBF

Question 6

• How is high renin, salt-resistant hypertension treated?

Answer 6

ACE inhibitors, ANG receptor blockers, beta blockers (inhibit renin)

Question 7

How is low renin, salt sensitive hypertension treated?

Answer 7

Low sodium diet, diuretics, Ca channel agonists & alpha 1 blockers (both decrease TPR)

Question 8

• What is the effect of blocking nitric oxide or prostaglandins?

Answer 8

Reduces ability to concentrate urine and preserve sodium balance (to maintain normal BP)